/* Copyright (C) 1991, 1992 Free Software Foundation, Inc.
This file is part of the GNU C Library.

The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Library General Public License as
published by the Free Software Foundation; either version 2 of the
License, or (at your option) any later version.

The GNU C Library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
Library General Public License for more details.

You should have received a copy of the GNU Library General Public
License along with the GNU C Library; see the file COPYING.LIB.  If
not, write to the Free Software Foundation, Inc., 675 Mass Ave,
Cambridge, MA 02139, USA.  */

#include <ansidecl.h>
#include <stddef.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <limits.h>
#include <errno.h>

/* Read up to (and including) a TERMINATOR from STREAM into *LINEPTR
   (and null-terminate it). *LINEPTR is a pointer returned from malloc (or
   NULL), pointing to *N characters of space.  It is realloc'd as
   necessary.  Returns the number of characters read (not including the
   null terminator), or -1 on error or EOF.  */

#define __validfp(f)	(f != NULL)

ssize_t
DEFUN(__getdelim, (lineptr, n, terminator, stream),
      char **lineptr AND size_t *n AND int terminator AND FILE *stream)
{
	char *line, *p;
	size_t size, copy;

	if (!__validfp (stream) || lineptr == NULL || n == NULL)
	{
		errno = EINVAL;
		return -1;
	}

	if (ferror (stream))
		return -1;

	/* Make sure we have a line buffer to start with.  */
	if (*lineptr == NULL || *n < 2) /* !seen and no buf yet need 2 chars.  */
	{
#ifndef	MAX_CANON
#define	MAX_CANON	256
#endif
		line = realloc (*lineptr, MAX_CANON);
		if (line == NULL)
			return -1;
		*lineptr = line;
		*n = MAX_CANON;
	}

	line = *lineptr;
	size = *n;

	copy = size;
	p = line;

	/* Unbuffered stream.  Not much optimization to do.  */
	while (1)
	{
		size_t len;

		while (--copy > 0)
		{
			register int c = getc (stream);
			if (c == EOF)
				goto lose;
			else if ((*p++ = c) == terminator)
				goto win;
		}

		/* Need to enlarge the line buffer.  */
		len = p - line;
		size *= 2;
		line = realloc (line, size);
		if (line == NULL)
			goto lose;
		*lineptr = line;
		*n = size;
		p = line + len;
		copy = size - len;
	}


lose:
	if (p == *lineptr)
		return -1;
	/* Return a partial line since we got an error in the middle.  */
win:
	*p = '\0';
	return p - *lineptr;
}

#undef __getline

/* Like getdelim, but always looks for a newline.  */
ssize_t
DEFUN(__getline, (lineptr, n, stream),
      char **lineptr AND size_t *n AND FILE *stream)
{
  return __getdelim (lineptr, n, '\n', stream);
}
